Excellent article sur l'Histoire du mastering
By Thomas, Apr 23 2014 09:56AM
Je reposte ici un article en Anglais trouvé sur le site du magazine Recording sur l'évolution du mastering depuis l'ère des 78 tours jusqu'à aujourd'hui.
Je l'ai sélectionné car je le trouve très bien documenté et aussi très bien écrit, une combinaison rare de nos jours.
Mastering Then and Now
The history of mastering
By Robert Auld
In the beginning, record mastering was not a separate discipline. If you were a recording engineer, your recording machine was a disc-cutting lathe. Prior to 1925, this tool of our trade was rather primitive—the cutting stylus was connected to a diaphragm which was powered by a large acoustical horn, and the turntable motor was spring-powered. By the 1930s electricity had entered the picture and that newfangled invention of the radio studios, the microphone, drove the cutting stylus through an amplifier. Regardless, the wax discs you cut were then used to make stampers from which shellac-composite 78 rpm discs were pressed. This was record production before tape.
After World War II, tape recording and the micro-groove LP were introduced. For the first time a separate engineer was charged with cutting master discs from the recording session tapes. He was not necessarily called a “mastering engineer,” however; sometimes the terms “dubbing engineer” or “transfer engineer” were used. This reflected the belief that the tape-to-disc transfer was a technical step in record manufacturing, not much different from stamper plating or vinyl press operation. The attitude of many record labels, including some known for their technical excellence, was that the mastering engineer was not supposed to exercise artistic judgement.
Other large record companies of that time had other priorities, especially when it came to pop music production. The trend was to automate the tape-to-disk transfer as much as possible, in the interest of production efficiency. The first step in this direction was automated margin control, introduced in the mid-1950s, which allowed control of the spacing between the grooves of an LP by analog computer circuitry. It was definitely a step forward in record production, as it made possible record sides of up to (and even beyond) 30 minutes.
Another problem in mastering the LP was the tendency of real music to have a wider dynamic range than the system could comfortably accommodate. While recording to tape helped a little, chiefly due to analog tape’s tendency to round off sharp high-level transients (the tape saturates when hit with too much level), it was still possible to cut to disc waveforms that simply could not be played back—the stylus would literally jump out of the groove—or even to burn out the disc cutter head. The high-frequency boost of the RIAA recording curve made this latter event a possibility if the high-frequency content of the program material was not carefully controlled.
Specialized limiters and compressors were developed for use in record cutting, to protect against expensive events like cutter heads blowing up, and to ensure a more consistent final product. By the mid-1960s, the whole system had become sufficiently sophisticated that it was possible for an engineer to set up a master tape and cutting lathe and just let it run, churning out master discs, stopping only to change the tape and put a fresh lacquer disc on the turntable. Al Kooper has described the Columbia Records mastering suites during this period—a series of cubicles in which the engineers would spend their time reading the newspaper while the lathes cut discs.
It should be no surprise that this lack of human involvement did not always produce artistically satisfactory results. One of the worst examples of mindless mastering that I have heard was the initial LP release of The Band’s album Cahoots. Whoever was responsible (there is no mastering credit on the album) had fed the master tape signal into the system at much too hot a level. The limiters and compressors did their job so the record can still be played; it just sounds consistently loud—no dynamic range to speak of aside from the fade-outs at the end of tunes—and absolutely lifeless, as the dynamics controllers sucked the life out of the sound. Plenty of other examples could be cited. In any case, it was not a tolerable situation for artists who cared about how their records sounded.
It was not long before a few enterprising engineers realized there might be a demand for record mastering done with care and skill, and so the independent mastering studio was born. Among the first was The Mastering Lab, started in Los Angeles in the late 1960s by engineer Doug Sax. Following in his footsteps were other engineers—Bob Ludwig and Bob Katz in New York City, Bernie Grundman in Los Angeles, Denny Purcell in Nashville, etc.
What they all had in common were really good ears, attention to detail, skill in setting up and using the best possible equipment, and devotion to customer satisfaction. When you brought work to one of these engineers, you could be confident—if your master tape was any good at all—that the resulting record would sound as good as, or even better than, your tape. Word got around, and the work of the independent mastering engineers eventually influenced the entire industry, leading to a general upgrading of technical standards, even at the big, bottom-line oriented labels.
It is because of the work of Doug Sax, Bob Ludwig, and others that it became the normal practice to list the mastering engineer in the album credits. No longer was he or she just a faceless cog in record production. The Band, after the disappointing results with Cahoots, got Capitol Records to hire an independent mastering engineer for their next album, Moondog Matinee. The credit on the album reads, “Mastering Engineer: (as always) Bob Ludwig, Sterling Sound.”
Mastering engineers are still with us but, for the most part, they no longer cut acetate master discs from analog open reel tapes. Indeed, due to the changes in record production caused by the CD, what such engineers now do is better described as pre-mastering. In this process, the recording is brought into final shape and recorded on digital media that is then sent to the CD pressing plant.
It may seem like this would be an easier process compared to the task facing the mastering engineer in the LP era; the CD is an inherently more precise medium, without the mechanical quirks and limitations of analog disc recording. But the changes that have occurred in the industry as a whole have actually made the mastering stage of the record making process more complex.
Consider: In the days of the big record labels, each company would have staff engineers who would work to technical standards established by the company. There would be standards for calibrating tape recorders, level standards for all tapes recorded in the company studios, standard ways of interfacing equipment, etc. In some cases the record label engineers would actually have built much of the equipment that they were using.
Given this kind of controlled, organized environment, the tapes reaching the mastering suites could have a technical quality and consistency that would be predictable. The songs would already be in the order in which they would appear on the album, pauses between songs would be set by leader tape of the right length, levels would be pretty consistent, most equalization problems would have been dealt with, etc.
These days the sessions for a CD album could be recorded almost anywhere in the world, from large urban studios to somebody’s bedroom studio. The engineer responsible for the final mixes could be anybody, including the artist. This way of working does open up artistic possibilities that may not have been available in the more regimented big record label system, but it also means that there is no longer the kind of technical oversight that the old system offered.
For this reason, many mastering engineers now prefer that clients should not finish certain aspects of an album; that fade-outs, spacing between songs, final levels for each song and other such matters be left for the mastering stage. They know from experience that clients who attempt to provide a really finished product will often botch the job because of inadequate skills or equipment. In today’s fragmented, independent record business, technical competence cannot be taken for granted.